This invention relates to a method of delivering a repelling agent to an area occupied by birds so as to effectively drive the birds away from that area.
Large numbers of birds are attracted to working landfills, airports, marinas, fish ponds, feed lots, golf courses and other large areas, creating a nuisance and human health hazards. The method of delivering a repelling agent established herein decreases the attractiveness of the area being protected to the birds so that the birds are driven to alternative areas, thus reducing conflict between humans and birds.
Numerous techniques for repelling birds from such areas have been used. These techniques include the use of pyrotechnics, bird distress calls, noise makers, visual deterrents such as hawk kites or balloons, and combinations of these methods. Though widely used, these methods are generally ineffective in repelling birds from a given area for more than relatively short periods of time, as the birds become habituated to whichever method or methods are selected. Periodically lethal methods must be used to reinforce other traditional bird control techniques.
It is also known to use chemical bird aversion agents to repel birds from a particular material treated with such agents. For example, chemical bird aversion agents have been used as a feed additive to deter birds from consuming otherwise edible materials, and as a coating to deter birds such as chickens from pecking and injuring one another.
All the methods suggested previously for repelling birds using chemical bird aversion agents rely on the birds ingesting the chemical agents. The methods are ineffective if the birds do not happen to feed on or peck on the treated objects.
Further, ingestion of the chemical bird aversion agents by the birds is a relatively inefficient mode of delivery for at least two reasons. First, chemical bird aversion agents are chemoirritants that work by stimulating the birds' trigeminal system (their facial sensory nerve system). If it is ingested, most of the chemical agent never accesses the receptors of the birds responsible for translating the physiological repellent signal to a behavioral response. The majority of the chemical agent passes to the gut where it is irrelevant as a warning signal.
Second, good chemical bird aversion agents are typically nonpolar and thus have low water solubility. These chemical agents can easily pass through the lipid layers at the receptor sites of the trigeminal system, but they generally are poor at passing through aqueous environments such as the mucous membrane linings in the mouth of a bird.
Because ingestion is an inefficient mode of delivery, it suffers from the drawback that high concentrations of chemical bird aversion agent are required to produce the desired repellent effect.
In a different field, chemical fogging has been used to kill insects such as mosquitoes. A chemical fog consists of an organic solvent such as a volatile hydrocarbon, and a chemical agent such as an insecticide dissolved in the solvent. However, due to environmental regulatory restrictions the use of volatile, hydrocarbon-based solvents has recently come under strict control.
In view of the drawbacks associated with relying on birds to ingest the chemical bird aversion agents, it would be desirable to provide an effective method of repelling birds regardless of whether or not the birds attempted to feed on or peck on treated objects. It would also be desirable to provide a method which does not require high concentrations of chemical bird aversion agent to be effective. It would also be desirable to provide a method to which birds are not readily habituated, so that such method was effective in repelling birds from an area for relatively long periods of time. It would also be desirable to provide a method which does not require the use of organic solvents.